Presentation pdf

Correlation between Radial Variation and
Mechanical Properties of Laminated Veneer
Lumber made from 14 Poplar Cultivars
Istie RAHAYU, PhD Student Double Degree Indonesia-France
Louis DENAUD, Ass. Pr. in Art et Métiers ParisTech, France
Remy MARCHAL, Pr., CIRAD, France
Wayan DARMAWAN, Pr., in Bogor Agricultural University, Indonesia
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Materials &
methods
Results and
discussion
IUFRO – MEMOWOOD
Introduction
The veneer processing industry use
almost exclusively one poplar cultivar
(I-214) for light packaging products.
In case of a disease, this could lead
to a shortage of raw material or a
significant loss in wood quality
(Haouzali 2009). Consequently it is
necessary to diversify the source of
genetic material.
Conclusion
France is the largest grower of poplar in
Europe. It had 236,000 ha (FAO 2008).
Total poplar harvesting in 2009 was 1,3
million m3 (FCBA 2011)
Istie RAHAYU
2 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction (2)
Introduction
Materials &
methods
1) Less lumber defect (knots, cracks and other defects)
2) Stable in dimension and more resistant to warp, twist, bow, and cup;
3) Available in large dimensions
Results and
discussion
Conclusion
Istie RAHAYU
3 / 18
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
IUFRO – MEMOWOOD
Objective
Introduction
Materials &
methods
The objectives of this research were to analysed
the effect of juvelinity and veneer thickness on
mechanical properties in each 14 poplar cultivar
Results and
discussion
Conclusion
Istie RAHAYU
4 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Sample Preparation
Introduction
Materials &
methods
Results and
discussion
Conclusion
Type B : sapwood veneer of 3 mm
•
Making 7 layer of veneers
•
Non destructive and
destructive test of
mechanical properties
Type D: false heartwood veneer of
3mm
•
Making 7 layer of veneers
•
Non destructive and
destructive test of
mechanical properties
Type E: sapwood veneer of 5,25
mm
•
Making 4 layer of veneers
•
Non destructive and
destructive test of
mechanical properties
Type F: false heartwood veneer of
5,25mm
•
Making 4 layer of veneers
•
Non destructive and
destructive test of
mechanical properties
Istie RAHAYU
5 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
LVL Production
Veneer Selection
Poplar cultivars : Brenta, Dvina, I-214, Koster,
Lambro, Lena, Mella, Soligo, Taro, A4A, Alcinde,
Polargo, Trichobel, Triplo
Introduction
Materials &
methods
Results and
discussion
Conclusion
From each log, we manufactured two types of
panels:
- A panel made of "adult" veneer (type B and E);
- A panel made of juvenile veneer (from false
heartwood - type D and F).
We made LVL of 7 layer from 3 mm veneer and
4 layer from 5.25 mm veneer, so that the average
thickness of our LVL was 21 mm.
All of veneers had already been dried until they
reached 8 - 10% of moisture content.
Istie RAHAYU
6 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Gluing Process
We used PVAc (Poly Vinyl Acetat) as adhesive. The vinyl
adhesive that we used was marketed under the name "Rakoll®"
_GXL 4. It is in the form of an emulsion and ready for
application.
We produced 188 LVL panels of 21 mm thickness and 500 mm
x 500 mm surface
Materials &
methods
Results and
discussion
Conclusion
Istie RAHAYU
7 / 18
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Materials &
methods
Results and
discussion
IUFRO – MEMOWOOD
Preparation Samples for Mechanical Properties
Each board was cut into standardized test
samples (EN 789), parallel to grain with
10 samples for each board specimens for
testing non-destructive characterization
and static bending.
BING: 3720 (1860 x 2) samples
static bending and MOR : 1860 samples
The parameter that we used for
mechanical properties were Modulus of
Elasticity (MOE) and Modulus of Rupture
(MOR) computed according to the
procedure detailed into the norme EN310.
Conclusion
Istie RAHAYU
8 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Non destructive (BING) and Destructive Test (Instron)
Introduction
Brancheriau L
Materials &
methods
Results and
discussion
Conclusion
• 4 point bending
• Load range of 5000 N at a
constant speed 5mm/min
until the samples broke
• Obtained MOE and MOR
Istie RAHAYU
9 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Density
Introduction
Materials &
methods
Results and
discussion
Conclusion
The equilibrium moisture content was very homogeneous (8.5 ± 0.5%).
There was a very good correlation between the densities of LVL made
from veneer 3 and 5 mm and densities of solid wood (R2 = 0.81 and 0.78
for 3 and 5 mm subsequently) (Figure top)
These results were very satisfactory from the point of view of the
homogeneity of the samples that we used in this research.
Istie RAHAYU
10 / 18
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
IUFRO – MEMOWOOD
Modulus of Elasticity (1)
Introduction
Materials &
methods
Results and
discussion
Conclusion
(Figure top) showed the correlation between MOE Static and MOE Dynamic for all
samples tested (LVL in flatwise and edgewise direction) (1903 samples, 3mm thick
veneers). The correlation was excellent (r2 = 0.93).
This indicated that BING was a reliable non destructive instrument for mechanical
grading Poplar based on MOE.
It was correspondence with Haouzali (2009), noticed the same relationship between
dynamic and static module of Poplar LVL (correlation coefficient (r) of the regression is
0.88 and the determination coefficient (r2) is 0.77, with highly statically significant at the
1% level). It was also shown that the dynamic MOE is always slightly higher than the
static MOE.
The resonance method is interesting to predict stiffness which is often penalizing poplar
form mechanical classment. Industrial control plywood and LVL boards could be
possible with BING method (Haouzali 2009).
Istie RAHAYU
11 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Materials &
methods
Results and
discussion
Conclusion
MOE (2)
The MOE values that we used
were the average values from
LVL made from 3 mm and 5 mm
veneers in flatwise and
edgewise bending test. The
results were very well correlated
with MOE of solid wood (Figure
Top), in line with Haouzali
(2009)
However, as Haouzali (2009)
observe it, the MOE of LVL were
generally lower than the MOE of
solid wood.
Thus, for the LVL, there were
cultivars with high rigidity values
(Lambro, Brenta, Taro, Alcinde,
Soligo, Lena, Koster) and three
cultivars (I214, A4A and Triplo)
were unsuitable for structural
applications (Figure Down).
Istie RAHAYU
12 / 18
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
IUFRO – MEMOWOOD
Modulus of Rupture (MOR)
Introduction
Materials &
methods
Results and
discussion
Conclusion
The comparison of the MOR values between LVL and solid wood also showed
a good correlation. The effect of lamination combined with adhesive performed
significantly improved the MOR of these cultivars (about 20% on average
compared to solid wood)
The poplar LVL and plywood proprieties can be influenced considerably by the
cultivar, the glue type and the veneer thickness (Haouzali 2009).
Istie RAHAYU
13 / 18
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
IUFRO – MEMOWOOD
Effect of Radial Position
Introduction
Materials &
methods
Results and
discussion
Conclusion
Istie RAHAYU
14 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Materials &
methods
Results and
discussion
Conclusion
Effect of Radial Position
The advantage of using veneers taken from sapwood , and therefore
supposed to be less juvenil than heartwood, is obvious since the
mechanical properties are much better (between 14 to 21%) for a
comprarble density (Table down). This proved that there was an effect
due to juvelinity in every poplar cultivar. It also showed that LVL from 5
mm veneers had the highest increase percentage from juvenile to mature
in MOE dynamic, MOE quasistatique MOR and density, 16%, 18%, 21%
and 2% subsequently.
Mean Value of 14 Poplar
Cultivars
LVL 5
mm
Mature
Juvenile
gain in %
LVL 3
mm
Mature
Juvenile
gain in %
MOE
dynamique
(MPa)
9429
8126
MOE
quasistatique
(MPa)
9129
7737
+16
MOR (Mpa)
Density
(kg/m3)
54
45
400
390
+18
+21
+2
9259
8193
8769
7629
56
48
417
412
+13
+15
+16
+1
Istie RAHAYU
15 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Conclusion
• BING, was reliable instrument for estimating MOE from destructive
test. Some cultivars have a real potential for structural
applications (Lambro, Soligo, Alcinde, Brenta and Taro) while
others could be excluded (A4A, I-214, Triplo).
Introduction
Materials &
methods
Results and
discussion
Conclusion
• All cultivars could be well peeled and presents an excellent
peelability as [NURBAITY.2012]. General cutting conditions used
for I214 were applied for the 14th cultivars.
• There was significant variation sapwood to heartwood (supposed
mature to juvenile wood) for each cultivar. The difference of mean
MOE and mean MOR between juvenile and mature LVL were 15%
and 17% for an increase of density of 1%. Finally, the use of
thicker veneers reduced the use of adhesive, simplified and
accelerated the production of panels without altering their
mechanical properties.
Istie RAHAYU
16 / 18
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Introduction
Materials &
methods
Results and
discussion
Conclusion
References
[CRPF]. 2013. Bilan du programme de restitution TRANSPOP 2 (programme
transfrontalier entre les régions Nord Pas de Calais - Picardie et la Belgique sur le
peuplier), présenté mercredi 5 décembre 2012
Denaud LE. 2006. Analyses vibratoires et acoustiques du déroulage [Tesis]. Cluny:
Sciences des Métiers de l’Ingénieur, Arts et Métiers.
Haouzali EH. 2009. Effets cultivar et station sur les propriétés mécaniques de LVL et
contreplaqués issus du déroulage de peupliers [Tesis]. Cluny: Sciences des Métiers de
l’Ingénieur, Arts et Métiers
Haouzali EH, Marchal R, Bleron L, Butaud JC. 2010. Effets cultivar et stations sur la
déroulabilité du peuplier et la qualité des produits issus du déroulage (dossier: qualités
du bois de peuplier). Forêt entreprise. 191: 22-26
Kretschmann DE, Moody RC, Pellerin RF, Bendtsen BA, Cahill JM, McAlister RH &
Sharp DW. 1993. Effect of Various Proportion of Juvenile Wood on Laminated Veneer
Lumber. Forest Product Laboratory Research Paper FPL-RP-521.
Kretschmann DE, Alden HA & Verrill S. 1997. Variation of Microfibril Angle in Loblolly
Pine Comparison of Iodine Crystallization and X-Ray Diffraction Technique. The
Proceeding of The IAWA/IUFRO International Workshop on The Significance of
Microfibril Angle to Wood Quality. Westport, New Zealand.
Nurbaity. 2012. Etude de la déroulabilité de 14 cultivars de peupliers : Analyse des
efforts de coupe et de l’état de surface des placages . MASTER STVE Sciences et
Technologies du Vivant et de l’Environnement, Mention Aliments et bioproduits,
Nutrition, Santé, Spécialité BF2E Bois, Fibres, Énergie, Environnement
Istie RAHAYU
17 / 18
Thank You – Merci Beaucoup – Terima Kasih
Any Questions ?
Doctorants LaBoMaP
IUFRO – MEMOWOOD
2 october 2013
Arts et Métiers
ParisTech
Centre de Cluny
Density
Introduction
Materials &
methods
Results and
discussion
Conclusion
The equilibrium moisture content was very homogeneous (8.5 ± 0.5%).
There was a very good correlation between the densities of LVL made
from veneer 3 and 5 mm and densities of solid wood (R2 = 0.81 and 0.78
for 3 and 5 mm subsequently) (Figure top)
These results were very satisfactory from the point of view of the
homogeneity of the samples that we used in this research.
The observed discrepancy between the densities of LVL 3 and 5mm was
systematic (intercept of linear regressions difference about 50 kg/m3) and
mainly due to the removal of three glue line between the two lay up. They
were about 30 kg/m3 because the weight adhesive application was about
200 g/m².
Istie RAHAYU
19 / 18